Issued Patents All Time
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 9770648 | Circuit puzzle | Kevin Daniel Norman, Penelope Anne Norman, Hiroshi Yamamoto | 2017-09-26 |
| 6116599 | Convertible interference sliding block type manipulable puzzle and method | Hiroshi Yamamoto | 2000-09-12 |